Except you still don't know what's the matter with his knee, and you definitely don't know what caused it. It seems a bit premature to assume that overtraining

Except you still don't know what's the matter with his knee, and you definitely don't know what caused it. It seems a bit premature to assume that overtraining was the cause, and it's pretty ridiculous to imply that because some runners have hurt their knees, it is unsafe, or pointless.